84 citations · 559 across the 13 of their papers we have counts for
13 papers
Entanglement and extreme planar spin squeezing
Giuseppe Vitagliano, Giorgio Colangelo, Ferran Martin Ciurana +3
We introduce an entanglement-depth criterion optimized for planar quantum squeezed (PQS) states. It is connected with the sensitivity of such states for estimating an arbitrary, no…
Entanglement-enhanced phase estimation without prior phase information
G. Colangelo, F. Martin Ciurana, G. Puentes +2
We study the generation of planar quantum squeezed (PQS) states by quantum non-demolition (QND) measurement of a cold ensemble of Rb atoms. Precise calibration of the QND me…
Simultaneous tracking of spin angle and amplitude beyond classical limits
Giorgio Colangelo, Ferran Martin Ciurana, Lorena C. Bianchet +2
We show how simultaneous, back-action evading tracking of non-commuting observables can be achieved in a widely-used sensing technology, atomic interferometry. Using high-dynamic-r…
Entanglement-enhanced radio-frequency field detection and waveform sensing
F. Martin Ciurana, G. Colangelo, L. Slodicka +2
We demonstrate a new technique for detecting components of arbitrarily-shaped radio-frequency waveforms based on stroboscopic back-action evading measurements. We combine quantum n…
Real-time shot-noise-limited differential photodetection for atomic quantum control
F. Martin Ciurana, G. Colangelo, Robert J. Sewell +1
We demonstrate high-efficiency, shot-noise-limited differential photodetection with real-time signal conditioning, suitable for feedback-based quantum control of atomic systems. Th…
Quantum non-demolition measurement enables macroscopic Leggett-Garg tests
Costantino Budroni, Giuseppe Vitagliano, Giorgio Colangelo +4
We show how a test of macroscopic realism based on Leggett-Garg inequalities (LGIs) can be performed in a macroscopic system. Using a continuous-variable approach, we consider quan…
Generation of macroscopic singlet states in a cold atomic ensemble
N. Behbood, F. Martin Ciurana, G. Colangelo +4
We report the generation of a macroscopic singlet state in a cold atomic sample via quantum non-demolition (QND) measurement induced spin squeezing. We observe 3 dB of spin squeezi…
Ultrasensitive Atomic Spin Measurements with a Nonlinear Interferometer
R. J. Sewell, M. Napolitano, N. Behbood +3
We study nonlinear interferometry applied to a measurement of atomic spin and demonstrate a sensitivity that cannot be achieved by any linear-optical measurement with the same expe…
Feedback-cooling of an atomic spin ensemble
N. Behbood, M. Napolitano, G. Colangelo +4
We describe a measurement-and-feedback technique to deterministically prepare low-entropy states of atomic spin ensembles. Using quantum non-demolition measurement and incoherent o…
Quantum atom-light interfaces in the gaussian description for spin-1 systems
Giorgio Colangelo, Robert J. Sewell, Naeimeh Behbood +2
We extend the covariance-matrix description of atom--light quantum interfaces, originally developed for real and effective spin-1/2 atoms, to include "spin alignment" degrees of fr…
Real-time vector field tracking with a cold-atom magnetometer
Naeimeh Behbood, Ferran Martin Ciurana, Giorgio Colangelo +3
We demonstrate a fast three-axis optical magnetometer using cold, optically-trapped Rb gas as a sensor. By near-resonant Faraday rotation we record the free-induction decay…
Certified quantum non-demolition measurement of a macroscopic material system
R. J. Sewell, M. Napolitano, N. Behbood +2
Quantum non-demolition (QND) measurements improve sensitivity by evading measurement back-action. The technique was first proposed to detect mechanical oscillations in gravity wave…
Planar squeezing by quantum non-demolition measurement in cold atomic ensembles
Graciana Puentes, Giorgio Colangelo, Robert J. Sewell +1
Planar squeezed states, i.e. quantum states which are squeezed in two orthogonal spin components, have recently attracted attention due to their applications in atomic interferomet…